// taken from http://stevenlevithan.com/assets/misc/date.format.js
/*
 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
 * MIT license
 *
 * Includes enhancements by Scott Trenda <scott.trenda.net>
 * and Kris Kowal <cixar.com/~kris.kowal/>
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */

var dateFormat = function () {
    var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
        timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
        timezoneClip = /[^-+\dA-Z]/g,
        pad = function (val, len) {
            val = String(val)
            len = len || 2
            while (val.length < len) val = '0' + val
            return val
        }

  // Regexes and supporting functions are cached through closure
    return function (date, mask, utc) {
        var dF = dateFormat

    // You can't provide utc if you skip other args (use the "UTC:" mask prefix)
        if (arguments.length == 1 && Object.prototype.toString.call(date) == '[object String]' && !/\d/.test(date)) {
            mask = date
            date = undefined
        }

    // Passing date through Date applies Date.parse, if necessary
        date = date ? new Date(date) : new Date()
        if (isNaN(date)) throw SyntaxError('invalid date')

        mask = String(dF.masks[mask] || mask || dF.masks['default'])

    // Allow setting the utc argument via the mask
        if (mask.slice(0, 4) == 'UTC:') {
            mask = mask.slice(4)
            utc = true
        }

        var _ = utc ? 'getUTC' : 'get',
            d = date[_ + 'Date'](),
            D = date[_ + 'Day'](),
            m = date[_ + 'Month'](),
            y = date[_ + 'FullYear'](),
            H = date[_ + 'Hours'](),
            M = date[_ + 'Minutes'](),
            s = date[_ + 'Seconds'](),
            L = date[_ + 'Milliseconds'](),
            o = utc ? 0 : date.getTimezoneOffset(),
            flags = {
                d: d,
                dd: pad(d),
                ddd: dF.i18n.dayNames[D],
                dddd: dF.i18n.dayNames[D + 7],
                m: m + 1,
                mm: pad(m + 1),
                mmm: dF.i18n.monthNames[m],
                mmmm: dF.i18n.monthNames[m + 12],
                yy: String(y).slice(2),
                yyyy: y,
                h: H % 12 || 12,
                hh: pad(H % 12 || 12),
                H: H,
                HH: pad(H),
                M: M,
                MM: pad(M),
                s: s,
                ss: pad(s),
                l: pad(L, 3),
                L: pad(L > 99 ? Math.round(L / 10) : L),
                t: H < 12 ? 'a' : 'p',
                tt: H < 12 ? 'am' : 'pm',
                T: H < 12 ? 'A' : 'P',
                TT: H < 12 ? 'AM' : 'PM',
                Z: utc ? 'UTC' : (String(date).match(timezone) || ['']).pop().replace(timezoneClip, ''),
                o: (o > 0 ? '-' : '+') + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
                S: ['th', 'st', 'nd', 'rd'][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
            }

        return mask.replace(token, function ($0) {
            return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1)
        })
    }
}()

// Some common format strings
dateFormat.masks = {
    'default': 'ddd mmm dd yyyy HH:MM:ss',
    shortDate: 'm/d/yy',
    mediumDate: 'mmm d, yyyy',
    longDate: 'mmmm d, yyyy',
    fullDate: 'dddd, mmmm d, yyyy',
    shortTime: 'h:MM TT',
    mediumTime: 'h:MM:ss TT',
    longTime: 'h:MM:ss TT Z',
    isoDate: 'yyyy-mm-dd',
    isoTime: 'HH:MM:ss',
    isoDateTime: 'yyyy-mm-dd\'T\'HH:MM:ss',
    isoUtcDateTime: 'UTC:yyyy-mm-dd\'T\'HH:MM:ss\'Z\''
}

// Internationalization strings
dateFormat.i18n = {
    dayNames: [
        'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat',
        'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'
    ],
    monthNames: [
        'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',
        'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'
    ]
}


dateFormat.polyfill = function () {
    // For convenience...
    
    /*jshint -W121 */
    Date.prototype.format = function (mask, utc) {
        return dateFormat(this, mask, utc)
    }
    /*jshint +W121 */
}

export default dateFormat
